1. Field of the Invention
This invention relates to hand wrappers for plastic film. More particularly, it concerns thermal cutters in such hand wrappers for cutting plastic wrapping films or the like by application of heat.
2. Description of the Prior Art
For wrapping or packaging goods in plastic films or the like, it has been known in the art to employ hand wrappers which generally consist of a heat cutter for thermally cutting a desired length of plastic film withdrawn from a supply roll and a heat sealer for thermally welding overlapped portions of wrapped film. The heat cutters in such hand wrappers are usually a single heater wire which is spanned transversely across the wrapper (see U.S. Pat. Nos. 3,131,278 and 3,579,949) or by a metal blade which is embedded with an elongated heater element (see U.S. Pat. No. 3,452,511). However, a difficulty is encountered in either case. Namely, in the case of the wire cutters, they are repeated subjected to film pressure and are susceptible to becoming disconnected, while in the blade cutters, they have large heat capacity and low response to heat rise, thereby requiring preheating before use with resultant waste of substantial amounts of energy.